Recently, liquid crystal displays (LCDs) have become one of the more popular flat panel displays that can be used as television and computer monitors, personal digital assistants (PDAs), and mobile phones, among other applications. As research for improvements to LCDs continues, various new ways of manufacturing LCD devices have been pioneered. For example, while the driving circuitry and the LCD panel were traditionally two separate layers that are attached together, gate driving circuit may now be directly formed on the LCD panel through a thin film process.
In the devices where the gate driving circuit is formed on the LCD panel using a thin film process, the gate driving circuit includes a shift register in which a plurality of stages are connected with each other in a cascade configuration. Each stage includes a plurality of transistors connected with one another to output gate voltages to the proper gate lines. While the output gate voltages function properly under normal conditions, some malfunctioning occurs when temperatures increases, causing a leakage current in the main transistor.
For the LCD device to function properly, the main transistor is to remain turned off during the duration that it is designed to remain in the OFF state, regardless of temperature. Hence, a method of keeping the main transistor in the OFF state even under extreme temperature conditions is desired.